Silyl-norbornene and interpolymers prepared of same

ABSTRACT

AN INTERPOLYMER FORMED BY THE ADDITION POLYMERIZATION OF ETHYLENE, AT LEAST ONE MONOOLEFIN HAVING THE GENERAL FORMULA CH2=CH-R, WITHOUT A POLYENE AND A SILYL NORBORNENE HAVING THE GENERAL FORMULA   1,3,7-TRI(R),2-((Y)M-SI(-X(3-(M+N)))(-(R&#39;&#39;)N)-5-NORBORNENE   IN WHICH R IS HYDROGEN, HALOGENATED OR UNHALOGENATED ALKLY, ARYLALKYL, ALKENYL OR 6- OR 7-ALKYLIDENE GROUP, R&#39;&#39; IS AN ALKYL, ARYL OR ALKENYL GROUP, X IS HYDROGEN AND Y IS HALOGEN, AND N AND M IS A NUMBER OF FROM 0 TO 2 SUCH THAT THE SOME OF M AND N IS NEVER MORE THAN 2.

United States Patent C) 3,838,115 SILYL-NORBORNENE AND INTERPOLYMERSPREPARED F SAME William C. Bond, Jr., Baton Rouge, La., assignor toCopolymer Rubber & Chemical Corporation No Drawing. Continuation ofabandoned application Ser. No. 112,069, Feb. 2, 1971. This applicationJan. 29,

1973, Ser. No. 327,704

lint. Cl. C081? 17/00 U.S. Cl. 260-8011 9 Claims ABSTRACT OF THEDISCLOSURE An interpolymer formed by the addition polymerization ofethylene, at least one monoolefin having the general formula CH =CH-R,with or without a polyene and a silyl norbornene having the generalformula in which R is hydrogen, halogenated or unhalogenated alkyl,arylalkyl, alkenyl or 6- or 7-alkylidene group, R is an alkyl, aryl oralkenyl group, X is hydrogen and Y is halogen, and n and m is a numberof from 0 to 2 such that the sum of m and n is never more than 2.

This is a continuation of application Ser. No. 112,069, filed Feb. 2,1971 now abandoned.

This invention relates to silyl-norbornenes and to new and improvedelastomers formed by interpolymerization of such silyl-norbornenes withethylene and one or more monoolefins having from 3-20 carbon atoms, withor without the addition of a polyene.

It is an object of this invention to produce a class of compoundshereinafter identified as silyl-norbornenes and to make use of suchsilyl-norbornenes as monomers in the preparation of interpolymers withethylene and one or more monoolefins having from 32() carbon atoms inthe manufacture of a terpolymer or with the addition of a polyene toproduce a sulfur vulcanizable EPDM type elastomer.

As used herein, the term silyl norbornene is meant to refer to a monomerhaving the general formula in which R is a halogenated or unhalogenatedalkyl group such as methyl, ethyl, propyl, isopropyl, butyl and the likesubstituted or unsubstituted alkyl group having from 1-18 carbon atoms,an aryl group such as benzyl, phenyl, naphthyl and the like, an arylalkyl group such as tolyl, xylyl and the like, alkenyl groups such asallyl, vinyl, crotyl and the like, or an alkylidene group in the 6- and7-position such as ethylidene, isopropylidene and the like; R is analkyl, aryl or alkenyl group as described above, X is hydrogen, n is anumber of from 0 to 2, Y is halogen and m is a number of from 0 to 2such that in plus n never totals more than 2. The silyl norbornenes,prepared in accordance with the practice of this invention arerepresented by -silyl 2 norbornene; 5-m0nochloro silyl-2-norbornene;5-dibromosilyl-2-norbornene; S-(ethylmethyl-silyl)-2-norbornene; 5silyl-6-ethyl-2-norbornene;

3,838,] 15 Patented Sept. 24, 1974 ice5-silyl-7-isopropylidene-2-norbornene; 1 benzyl-S-silyl-Z- norbornene;5- chloro-methyl-silyl -2-norbornene.

The silyl norbornenes of this invention can be prepared by reduction ofthe corresponding halosilyl norbornenes having the general formula asdescribed above in which the groups identified by the letters X and Yare highly hydrolyzable groups such as a halogen group as represented bychlorine, bromine and iodine, in which the X portion of the halogengroup is replaced by a hydrogen group by a reduction reaction.

The following example is given by way of illustration, and not by way oflimitation, of the preparation of the silyl norbornenes of thisinvention by reduction of the corresponding monodior trichlorosilylnorbornene;

Example 1 Dist. temp. Pressure Amount Fraction C.) (g.)

56*64 75 mm. 5.8 56-70 50 nun. 1.5 78-96 20 mm. 5.2 4 96 20 mm. 7.7-residue 17. 2

It was determined by a nuclear magnetic spectrum that fraction -1 was5-si1yl-2-norbornene with the following characteristic nuclear magneticabsorptions. C and C nirbornene group a=5.98; SiH group two doublets forexo and endo in a ratio of 5 to 16 centered at Ot=3.6 (1:3.5 c.p.s.) andoc=3.37 (1:3.5 c.p.s.). Ratio of SiH to C =C was 21 to 14. Thestructural formula is as follows:

It was found that fraction 2 contained large amounts of5-monochlorosilyl-2-norbornene which has the following structuralformula:

amounts of S-dichlorosilyl-2-norbornene which has the followingstructural formula:

Fraction 4 was predominantly the S-trichlorosilyl-Z- norbornene startingmaterial.

The described reduction procedure is a modification of a generalprocedure for the reduction of a chlorosilane with lithium aluminumhydride LiAlH, as first carried out by 3 Schlesinger and his co-workersand described in the Journal of the American Chemical Society, 69, 2692(1947).

Others of the halosilyl norbornenes can be substituted in equivalentamounts in Example 1 for the preparation of of the silyl norbornenes ofthis invention.

The silyl norbornenes of this invention are capable of additionpolymerization through the active unsaturated linkage of the norbornenylgroup attached to the silicon atom for interpolymerization with ethyleneand at least one monoolefin having from 3-20 carbon atoms, in thepreparation of a terpolymer, or with the further addition of a polyene,in the preparation of a tetrapolymer, to produce new and improved EPDMtype elastomers having many new and novel characteristics, which arecapable of sulfur vulcanization or cure, and more particularly arecapable of a peroxide cure possibly by addition of the SiH bond acrossan available double bond.

The monoolefin having from 3-20 carbon atoms may be represented by thegeneral formula RCH=CH wherein R is a C to C alkyl radical, which may bebranched or straight chained, halogen substituted or unsubstituted andwhich may be represented by the compounds propylene, l-butene,l-pentene, l-hexene, l-heptene, l-octene, l-nonene, l-decene,4-methyl-1-pentene, 4- methyl-l-hexene, 4,4-dimethyl 1 pentene,5-methyl-1- heptene, 6-methyl-1-heptene, etc. As the monoolefin, it ispreferred to make use of propylene with the ethylene and propylene orother monoolefin present in the interpolymer in the ratio of -95 molesof ethylene to 80-5 moles of propylene and preferably 45-90 moles ofethylene to 55-10 moles of propylene.

As the polyene, when present in the preparation of a tetrapolymer, usecan be made of an open chain polyunsaturated hydrocarbon containing 4-20carbon atoms, such as 1,4-hexadiene, a monocyclic polyene or apolycyclic polyene, but it is preferred to make use of a polyunsaturatedbridged ring hydrocarbon or halogenated bridged ring hydrocarbon such asthe polyunsaturated derivatives of bicyclo(2,2,1) heptane wherein atleast one of the double bonds is present in one of the bridged rings,such as dicyclopentadiene, bicyclo(2,2,1)hepta-2,5-diene, or alkylidenenorbornenes and preferably a 5-al'kylidene- 2-norbornene wherein thealkylidene group contains from 1-20 carbon atoms and preferably 1-8carbon atoms, or the alkenyl norbornenes, and preferably the5-alkenyl-2- norborness wherein the alkenyl group contains from 3-20carbon atoms and preferably from 31-10 carbon atoms. Other bridged ringhydrocarbons include polyunsaturated derivatives of bicyclo(2,2,2)octane, as represented by bicyclo(2,2,2)octa-2,5-diene, polyunsaturatedderivatives of bicyclo(3,2,1)octane, polyunsaturated derivatives ofbicyclo(3,3,1)nonane. At least one double bond is present in the bridgedring of the above compounds and at least one other double bond ispresent in a bridged ring or in a side chain. Specific examples ofpreferred bridged ring compounds of the type described above includeS-methylene-2-norbornene, 5-ethylidene-Z-norbornene,S-n-propylidene-Z-norbornene, 5-isopropylidene-2-norbornene,5-nbutylidene-2-norbornene, 5 isobutylidene-Z-norbornene,dicyclopendadiene, 5-(2-methyl-3-butenyl)-2-norbornene,5-(3-methyl-2-butenyl) norbornene and 5-(3,5-dimethy1-4-hexenyl)-2-norbornene. The interpolymer prepared fromS-ethylidene-2-norbornene is greatly preferred since the combinationwhich makes use thereof has outstanding properties and it appears to besomewhat unique by reference to the others.

The polyene or substituted polyene may be chemically bound in theinterpolymer in an amount within the range of 0.1 to 10 mol percent, andpreferably 0.1 to 3 mole percent, or in an amount to provide an actualor calculated unsaturation level of at least two double bonds per 1000carbon atoms of the interpolymer chain. However, amounts to provide muchhigher unsaturation levels are preferred, such as levels of up to 100double bonds per 1000 carbon atoms in the interpolymer, and preferablyan amount to provide from 2.5 to 30 double bonds per 1000 carbon atoms,and more preferably 2.5 to 15 double bonds per 1000 carbon atoms. Thespecific unsaturation level selected to be introduced by the polyenecomponent will vary depending upon the properties desired in theelastomeric interpolymer that is formed.

The silyl norbornene can be employed in the interpolymerization reactionmixture in an amount within the range of 0.05 to 20 percent by weightand preferably in an amount within the range of 0.1 to 5.0 percent byweight of the total monomer mixture.

The interpolymerization of the monomeric components described can becarried out in solution in an inert organic solvent, in the presence ofa Ziegler type catalyst, all of which will hereinafter be described.

The polymerization solvent may be any suitable inert organic solventwhich is liquid under the reaction conditions such as any prior artsolvent useful for solution polymerization of monoolefins in thepresence of Ziegler type catalysts. Examples of satisfactory hydrocarbonsolvents include straight chain halogenated or unhalogenated paraffinscontaining 5-8 carbon atoms, and preferably hexane and chlorohexanes;aromatic hydrocarbons and preferably halogenated or unhalogenatedaromatic hydrocarbons containing a single benzene nucleus such asbenzene, hexachlorobenzene, toluene and the like; saturated cyclichydrocarbons which have a boiling point range approximating that for thestraight chain paraffin hydrocarbons and aromatic hydrocarbons discussedabove, and preferably saturated cyclic halogenated or unhalogenatedhydrocarbons containing 5 or 6 ring carbon atoms. The solvent may be amixture of one or more of the foregoing hydrocarbons, such as a mixtureof aliphatic and naphthenic hydrocarbons, preferably havingapproximately the same boiling range as normal hexane. It is importantfor the solvent to be dry and free of substances which will interferewith the Ziegler catalyst to be used in the polymerization process.

Ziegler catalysts, as described in the prior art, may be employed. SuchZiegler catalysts are disclosed in a large number of patents, such asUS. Pat. No. 2,933,480, No. 3,093,620, No. 3,093,621, No. 3,211,709 andNo. 3,113,115. Such Ziegler catalysts generally include metal organiccoordination catalysts prepared by contacting a compound of a heavymetal of the groups IV!) to VIIb of the Mendelejetf periodic system ofelements, such as titanium, vanadium and chromium halides with anorganometallic compound of a metal of Groups I to In of the Mendelejetfperiodic system which contains at least one carbon-metal bond, such astrialkyl aluminum and alkyl aluminum halides wherein the alkyl groupscontain from 1-20 and preferably 1-4 carbon atoms.

The preferred Ziegler catalyst for the described polymerization isprepared from a vanadium compound and alkyl aluminum halide such asvanadium trichloride, vanadium tetrachloride, vanadium oxychloride,vanadium acetylacetonate, etc., and alkyl aluminum chloride activatorshaving the general formula R AlCl and R AlCl, and the correspondingsesquichlorides having the general formula R Al Cl in which R is methyl,ethyl, propyl, butyl or isobutyl. In the catalytic system, the aluminumto vanadium mole ratio of the aluminum and vanadium compounds may bewithin the range of 5-200:1 and preferably within the range of 15-60: 1.A catalyst prepared of alkyl aluminum sesquichloride, such as methyl orethyl aluminum sesquichloride, and vanadium oxychloride is preferred,with the preferred ratio of 1 mole vanadium oxychloride for 5-200 molesof aluminum and preferably for each 15-60 moles of aluminum.

Generally the polymerization reaction may be carried out in atemperature range of 40 to 150 C. and preferably within a temperaturerange of 20 to C. during the course of the reaction. The polymerizationreaction may be carried out at substantially atmospheric pressure butpressures up to 1000 psi. may be employed.

The polymerization is preferably carried out on a continuous basis in adry reaction vessel which is closed to the outside atmosphere and whichis provided with means for agitation, reactor cooling means, and inletsand outlets for continuously supplying the ingredients of the reactionmixture including the monomer and catalyst, and for continuouslywithdrawing the solution of elastomer. The polymerization is carried outin a liquid phase in the organic solvent in the presence of the Zieglercatalyst and the solution of elastomer in the polymerization solvent iswithdrawn continuously from the reaction vessel and the catalyst iskilled by a catalyst deactivator.

The tetrapolymers of the invention may be cured in accordance with priorart procedures. As a general rule, a curing procedure which is normallyfollowed in curing highly unsaturated hydrocarbon rubbers, such asstyrenebutadiene rubber, natural rubber, polybutadiene rubber, syntheticpolyisoprene rubbers and the like, will be satisfactory. Use may be madeof various curing agents in effecting the rapid cure of theinterpolymer.

Conventional fillers and pigments may be formulated with theinterpolymer, such as to 200 parts by weight of carbon black, finelydivided silica, esterified silica, titanium dioxide, kaolin and whiting,per 100 parts by weight of rubber. It is also possible to extend theinterpolymer with oil such as extender oils as represented by naphthenicoils usually added in an amount of 10 to 100 parts and preferably to 80parts per 100 parts by weight of rubber.

Vulcanization is accomplished by heating the compounded interpolymer ata vulcanizing temperature for a period of time suflicient forvulcanization, such as at a temperature above 130 C. for 10 to 90minutes, and preferably within the range of l60180 C. for about minutes.

When carrying out a free radical cure of the interpolymer and compoundsformed thereof, a heat activated free radical curing agent is admixedwith the interpolymer and the mixture is heated to a sufliciently hightemperature to activate the curing agent for cure over a practicalperiod of time. Usually temperatures of 50 to 175 C. for a period ofseveral minutes to several hours is sufiicient. Preferred free radicalcuring agents include organic peroxides such as dicumene hydroperoxide,dibenzoyl hydroperoxide, cumene hydroperoxide andditertiarybutylperoxide.

The cured elastomers and compounds of this invention may be used in awide variety of articles including tires, belts, hose, tubing and thelike.

Having described the basic concepts of the preparation of an EPDMinterpolymer using the silyl norbornene of this invention as a monomericcomponent thereof, the following examples are given by way ofillustration, but not by way of limitation:

Example 2 This example illustrates the preparation of an EPDM typeinterpolymer which makes use of three monomeric components includingethylene, propylene and the silyl norbornene of this invention.

A dry flask was first flushed with nitrogen gas and filled with 100 cc.of dry hexane which was flushed with polymerization grade propylene andpressured to 15 p.s.i.g. with propylene. The flask was brought to 25p.s.i.g. total molecular pressure by addition from a feed tankcontaining 65 mole percent ethylene and mole percent propylene.Polymerization was carried out in a water bath maintained at 35 C.Additions were made to the flask of 0.02 mM. butyl perchlorocrotonate,1.45 mM. of the silyl norbornene prepared in Example 1, 0.3 mM. ethylaluminum sesquichloride and 0.005 mM. vanadium oxytrichloride.

As the polymerization proceeded, the monomer composition in ethylene andpropylene was maintained constant by continuous addition from the feedtank. At 300 seconds and again at 600 seconds, 0.58 mM. silylnorbornene, 0.02 mM. butylperchlorocrotonate, 0.18 mM. ethyl aluminumsesquichloride and 0.005 mM. vanadium oxytrichloride were charged to theflask and at 900 seconds 1.0 cc. isopropanol containing 0.05 g. ofIrganox was added. The polymer cement was mixed with water to removecatalyst. The polymer was precipitated out of solution with cc. ofisopropanol, then redissolved in hexane, then reprecipitated withisopropanol. After drying in a vacuum oven at 75 C. for 12 hours, theresulting product (4.2 g.) was clear and gel-free.

Example 3 This example represents the preparation of an EPDM typeinterpolymer of all four monomers including ethylene, propylene, polyeneand the silyl norbornene of this invention.

A cement was prepared as in Example 1 but with the polyene component,namely the S-ethylidene-Z-norbornene.

The resulting cement was treated as in Example 2.

Example 4 Others of the silyl norbornene compounds identified on pages 1and 2 of the specification may be substituted in equivalent amounts forthe 5-silyl-2-norbornene of Example 1 and the silyl norbornene ofExample 2.

The interpolymers of this invention, as represented by Examples 1 to 4,have a number of unique and desirable characteristics which make themuseful in a number of commercial applications:

The interpolymers have good compatibility and cocurability with otherunsaturated polymers, preferably elastomers. The interpolymers of thisinvention are capable of cocure with SBR since the bond of theunsaturated silyl group is capable of adding readily across a doublebond in the presence of traces of peroxide.

The interpolymers of this invention provide improved physical propertiesin mineral filled compositions due to the greater polarity of the Si-Hbond.

The Si-H bond tends to produce interpolymers having properties similarto the properties of a silicone fluid insofar as surface characteristicsare performed. The nonwettability of the surface permits relativemovement between surfaces with a minimum amount of drag or interfacialfriction.

The silyl component is effective to improve the interbonded relationshipbetween the interpolymer and glass in the manufacture of glass fiberreinforced products as well as improved adhesion to other materials suchas resins, metals and the like.

It will be understood that changes may be made in the details offormulation and composition without departing from the spirit of theinvention, especially as defined in the following claims.

I claim:

1. A solid interpolymer formed by addition polymerization of a mixtureof monomers consisting essentially of ethylene, at least one monoolefinhaving the general formula CH =CHR in which R is a halogen substitutedor unsubstituted Ch-C alkyl radical, branched or straight chained, and amonomer silyl norbornene which enters into the polymerization throughthe unsaturated linkage of the norbornenyl group attached to the siliconatom and which has the general formula l ml in which R is a groupselected from the group consisting of hydrogen, halogenated orunhalogenated alkyl, aryl, arylalkyl, alkenyl and 6- or 7-alkylidenegroup, R' is a group selected from the group consisting of alkyl, aryland alkenyl, X is hydrogen and n is a number of from to 2, and in whichethylene and monoolefin are present in the polymer in the mole ratio of20-95 moles of ethylene to 85-5 moles of monoolefin, and the monomer ispresent within the range of 0.05 to 20% by weight of the total amount ofmonomeric material in the mixture.

2. A solid interpolymer formed by addition polymerization of a mixtureof monomers consisting essentially of ethylene, at least one monoolefinhaving the general formula CH =CHR in which R is a halogen substitutedor unsubstituted C -C alkyl radical, branched or straight chained, anon-conjugated polyene, and a monomer silyl norbornene which enters intothe polymerization through the unsaturated linkage of the norbornenylgroup attached to the silicon atom and which has the general formula 3--(mm) n which ethylene and monoolefin are present in the interpolymer inthe mole ratio of 20-95 moles of ethylene to 5 moles of monoolefin, themonomer is present within the range of 0.05-20% by weight of the totalamount of monomeric material in the mixture, in which the polyene ischemically bound in the interpolymer in an amount Within the range of0.1-10 mole percent.

3. An interpolymer as claimed in Claim 1 in which the monoolefin ispropylene.

4. An interpolymer as claimed in Claim 2 in which the monoolefin ispropylene.

5. An interpolymer as claimed in Claim 2 in which the polyene is boundin the interpolymer in an amount within the range of 0.1 to 3 molepercent.

6. An interpolymer as claimed in Claim 1 in which the silyl norbornenemonomer is present in an amount within the range of 0.1 to 5 percent byweight.

7. An interpolymer as claimed in Claim 2 in which the silyl norbornenemonomer is present in an amount within the range of 0.1 to 5 percent byweight.

8. An interpolymer as claimed in Claim 2 in which the polyene is apolyunsaturated bridged ring hydrocarbon.

9. An interpolymer as claimed in Claim 2 in which the polyene is5-ethylidene-2-norbornene.

References Cited UNITED STATES PATENTS 2,847,409 8/1958 DeBenneville etal. 260-897 3,240,768 3/1966 Guenther 26088.1 3,375,236 3/1968 Van deCastle et al. 26080.71

STANFORD M. LEVIN, Primary Examiner U.S. Cl. X.R. 260-4482 E

